Method of making dies.



.I. M. LYNCH.

METHOD OF MAKING DIES.

APPLICATION FILED SEPT. 25. 1911.

Patented Nov. 16, 1915.

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JOHN M. LYNCH, OF BEVERLY, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE MACHINERY COMPANY, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

To all whom it may concern."

Be it known that'I, JOHN M. LYNCH, a citizen of the United States, residing at Beverly, in the'county of Essex and State of Massachusetts, have invented certain Improvements in Methods of Making Dies, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figures.

This invention relates to methods of making dies of the type used in connection with a clicking press for cutting upper leather for boots and shoes. v V More especially the invention relates to a novel method of" making dies having lateral indentations or nicks in their cutting edges for the purpose of indicating the size of the blanks out out by the die or for indicating amount of lap in assembling the blanks or the location of the lines of stitch- It is an object of the present invention to devise a method by which dies of this character may be produced by a process of castingas distinguished from the process therein described which involves forging and welding. The production of such dies on an economical basis presents many difliculties, not only from the nature of thedies themselves and the accuracy required in their construction, but also because of the fact that rarely are two dies of exactly the same contour required. To meet these conditions, therefore, it isimportant to devise a method whereby single dies of various shapes and sizes may be produced by following out a simple series of operations, each requiring in itself little or no skilled labor and involving little waste of material. it I 7 It is an object of this invention to devise such a method.

The method comprises,in certain of its important steps, the p'roduction'of', dies by first forming rough castings" ofacast iron having -projecting ribs on one side-thereof and subsequently converting the material ofthe castings into a semi-steel which will possess substantially all the-edge holding and shock resisting properties of mild steel, such properties as might be' found in steel, castings. By the present method, however, the expense incident to producing steel Specification of Letters Patent.

METHOD or MAKING DIES.

Patented Nov. 16, 1915.

Application filed September 25, 1911. Serial No. 651,254..

castings is avoided and a finished die is produced which is not inferior to a cast steel die. Having produced a rough casting a cutting edge of the desired contour is formed by grinding or filing one edge of the casting. A cutting edge of such shape as to form in the margin of each blank cut out by the die a notch of the requiredshape is then formed upon the end of the projecting rib. It is important that the notches in the blanksshould be disposed with great accuracy, particularly those which are intendedfor locating lines of stitching or lap of the blanks. The formation of a project ing rib on one side of the die casting facilitates the accurate location of the nick with respect to the previously formed cutting contour of the die by allowing the die maker suflicient' material adjacent to the cutting edge to permit the location of the nick to be varied slightly longitudinally of the edge of the die. On this account it is possible to compensate for inaccuracies between the pattern and the casting. Another advantage incident to this step 'of the method is that material of superior quality is" provided from which the nicks may be formed. It has been found that the cutting edges'of thenicks, which are subjected to a serious wedging action in use, will maintain their shape a much longer time if out out from athick section of the casting, such as the'ribs, than if formed from a thin casting which-is likely to include. surface scale.

Other advantages of the invention will be best "understood andbappreciated from the following description of a preferred manner of practising the method, the steps of which are illustrated in the accompanying drawings, in which:

Figure l is a view inperspective of a block or slab from which the pattern is to be produced in position upon a table. of a jig saw; Fig. 2 is a view in perspective of the partially sawed out pattern on the'table of a band saw; Fig. 3 is a view in perspece tive' of the completed pattern, a portion being broken away to show the shape of its cross section; Fig. 4 indicates the operation 4 of wax finishing the pattern and shows the wax receptacle and polishing brush; Fig. 5 indicates the-casting operation, and shows the mold and rough casting in cross section; Fig. 6 indicates the operation of'decarburizing the castingsfand shows several of them packed in iron scale in an annealing pot; Fig. 7- is a View in perspective of a complete vamp diea Y In forming these first provided having the outline of the blanks to be cut by the die, and therefore the desired outline of the cutting edgeof the die.

The paper pattern is furnished in duplicate by the shoe manufacturer, each manufacturer havinghis individual styles. lheoutline of he'n pe patte n isindicated. upo a board having a thickness equal to the height ofthe die. This operation may be effected by the use of a grading machine which may be arranged to mark upon the board outline-determined by the paper pattern-placed in the machine. If prefer able, however, one of the paper patterns may be pasted on the surface of the board. As but one or two dies are to be made from c pa rn, a one-p c b ard; Wil nswer all the requirements, although from a-laminated board composed ofthin sheets glued together a more durable pattern could be produced. In some cases however, it may be f und'p a tica emp oys la of wax i .1- stead of aboard as material from which to produce the pattern. Having indicated the desired outline 14 upon thepattern block or slab,12, asshown inFig. 1, the slab is perforated for the reception-of the blade 16 of a scroll saw and placed upon-the, table l0. The interior line of the pattern,;coin-v aid g.- With t e Ou line is t n saw d, out.

If it is desired to havethe inner surface of the die perpendicular to the cutting bed: of the clicking press sawing out the interior ofthe patternthe table 10 will be disposed at right/ anglesto-the saw blade 16,'so that the inner surface of the pattern will bepupendicular, but if an. interior bevelisdesired the table l0 may be set at a corresponding incli-n-ation-tothesaw. In case it is desired toproduce a die with size indicating inden- 'tationsin its cutting edge'proj ect ions 2-1 are left within the contour of 'thev pattern, and in; these projections 21 are subsequently carved corrugations'26 of the requiredshape extendingfrom one edge of the die to the other; If interiorbraces or bracketsare required corresponding bridges 22 or ears 2-4: will be sawed out as an integral part of thepattern when the'interior of -the pattern is; being sawed. The partiallyi'sawed'o-ut pattern is then placed upon thetable 18 of aband saw and the outer line, of the pattern is out out, The wedge shaped cross section desiredl in the die, indicated. by the section ,of the wooden pattern shown in Fig. 3,,is' v conveniently secured in the'flpattern by dis posing thestable '18 at an angle to thefsaw blade 20. Thepattern is sawed out with the edge uppermost which corresponds to the cutt ng e ge 02f. the-die, ndn; erv ng h dies a paper pattern is terial-sho-uld be as followsgfi outer line of the pattern it is necessary only to cause the saw to follow a line on the surface of the blockor slab 12 about one thirtysecond ofan-inch from the line 'l l'indicating the inner contoun- On account of the inclination of the table with respect to the saw the surface thus cut will diverge from the inner surface and will leave the back of r the pattern substantially the Width required by an end-cutting in'illing tool, Instead of I sah -p per ng and sm o hing thev sa ed o t pattern as has been usually done,.th e surface of: th Wo den. pat ern; sa ed; out n. he manner hereinbefore described,is filled with an smoo hed; r in r1 As indi ated in Fig. 4, the pattern isdipped in are'cepitacls 2 of m te W suc paraf in, for

xa pl nd its, urfa eip andsm o hed by the rotating brush 30. By theopetatifin abovefoutli-ned pattern is; produced "hav- -m th surfaces.- which; facilitate he draft of th pa n f m hesand the mold, a d a so 1; a. argesmsasure preven the warping effect of dampness, Having pr du e the wooden. p e n e ca ting; perat n ext t e PMQ As shown 7 in ig. hsm l i f rmed ti ly-i -ths v r lower flask 44,; While the plane surface; of the copel2 forms the back or pressure re- 7 i i in'g s face of h f l Q- Th meals gated in v the-si ss t e di f m; nt r, 7 the a g be ng; ndi a ed by r feren e character 4 0. 'lhernaterial. used for; the casting will be a good grade; of white iron, Itjis-prefera-ble that the analysis: of; he

(332.75 gtoaea Si" O.75 'tofjIL25' not over l-0 not over 0 23. When the rough castings have been p10 dated; an p kled: usual to? r m ve-the Total ag t 2;;s ch as iron-sc le, c o ed; n

sand, they are packed withgani QXlQllZiIlg V 50 as shown inEig, 6, and subjected to-heat sufficient to start/a, reactijen' between. th OXi dicing-agent and the carbon'of-the'castings,

the eat be g nt ued-untilmost efthe car n has bee xt a ed or converted to' temper carbon; It has been, found: that this re u t s' effected by sllzbjecting theacaste L 7 i gS:{ @i emperature fron f 14,50 E-Qto' M 0 a period; Of; b should; bQ TILQ. in by this opera:

out 48 hours it tion the castings are not converted into malleable iron, but as distinguished from malleable iron, still retain some carbon in the form of hardening carbon by reason of which it is possible to harden and temper the castings as though they were formed of steel. Material having these characteristics is herein designated as semi-steel. When the decarburizing of the castings has proceeded to the proper point the pct 50 is allowed to cool slowly with its contents. The castings are thus annealed and are in such condition that they may be readily machined. The first step in this operation consists in bringing the narrow edge of the casting, which is to be they cutting edge of the die, into one plane. This is effected in any convenient manner, as, for example, by Gardner grinding upon the side of a rotating disk. The other surface of the die is then brought into a plane parallel to the plane of the cutting edge, and this operation may be performed conveniently upon several castings at once whereby a uniform height is secured in the dies. After the castings have been reduced to uniform height and opposite surfaces brought into parallel planes, they are ground or filed upon their inner and outer surfaces into their final shape, the contour of the cutting edge being frequently compared with the outline of the original paper pattern used in producing the wooden pattern for the casting operation. At this time the ribs or corrugations 60' on the inner surface of the castings are given their characteristic contour by filing on their inner surface and by filing notches 63 in the outer edge of the casting. nicks may be shaped in accordance with any desired system such, for example, as the code disclosed in United States Letters Patent No. 990,218, granted April 25, 1911-on an application of T. H. Files. This method of producing the cutting indentations is of further importance, in that the corrugations which extend from one edge of thedie to the other on the inside more than compensate for weakness in the .die caused by filing the notches in its outer surface. The notches in the outer surface of the die need extend only a short distance back from the cutting edge. The bridges 62 and ears 64 require no machining except that the latter are drilled The size indicating to receive the stab point markers 61. When the die has been given its final shape and sharpened to a cutting edge, it may be hardened and tempered in any preferred manner. A convenient manner of tempering the die is disclosed in my prior Patent No. 1,029,877, granted June 18, 1912, and consists in heating the die by floating it, edge down, in molten lead having a coating of charcoal, and then hardening the die in oil.

A die constructed as above outlined may be left in a hard condition being drawn down only to a pale yellow temper. This is an important advantage of the invention in that it obviates the necessity of subjecting the hardened die to any considerable degree of heat, and therefore, lessens the liability of the finished die being distorted from its required shape.

Having now described my invention, I claim as newand desire to secure by Letters Patent of the United States 1. The method of making dies of closed contour having indicating notches therein which consists in casting a rough die having projecting ribs on its inner side, converting the casting into semisteel, finishing the casting, and interrupting the general contour of the die by forming cutting edges at the ends of the ribs and by cutting notches in the outer surface of the die opposite to the ribs which notches extend only a short distance fromthe cutting edge.

2. The method of making dies of closed contour having indicating notches therein,

which consists in casting a closed frame having the general contour desired in the die and having projecting ribs on one side thereof, converting the casting into semi-steel by suitable heat treatment, after such heat:

treatment shaping a cutting edge at one edge of the casting, and interrupting the general contour of the cutting edge by forming transversely offset nicks in the ends of the projecting ribs. I

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN M. LYNCH. Witnesses:

MABEL A. Swn'r'r, Cnns'rnn E. ROGERS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, 2

Washington, D. G. 

